Such surgical tool devices are used for working in tissue, especially bone tissue, such as in the region of vertebrae, for example, in order to remove tissue coming into contact with nerves there, also intervertebral disk tissue, or to create conditions for stabilization, such as the fixation of two vertebrae. The tools to be used are rotationally driven tools, such as drills or cutters. They are inserted microinvasively endoscopically. It is often very difficult or impossible to insert a tool device microinvasively endoscopically to its work site such that it is aligned with the insertion path and also with the axis of the tool device, without jeopardizing delicate organs, blood vessels or nerves over this path. It is therefore desirable or even necessary to select a working channel at the end of which the work site will be out of alignment with or is offset in relation to the working channel and the tool axis.